code: def test_doxygen_equation_markers(tmpdir):
      cfg_file = tmpdir.join("jupytext.toml")
      nb_file = tmpdir.join("notebook.ipynb")
      md_file = tmpdir.join("notebook.md")
  
      cfg_file.write(
          "hide_notebook_metadata = true\ndoxygen_equation_markers = true"
      )
      nb = jupytext.reads(SAMPLE_MARKDOWN, "md")
      del nb.metadata["jupytext"]
      nbformat.write(nb, str(nb_file))
  
      jupytext_cli([str(nb_file), "--to", "md"])
      md = md_file.read()
  
      # Doxygen equation markers
      assert "$$" not in md
      assert "\\f[" in md
      assert "\\f]" in md
      assert "\\f$" in md
      assert "\\f$" in md
  
      # Metadata hidden
      assert md.startswith("<!--\n\n---\n")
  
      jupytext_cli([str(md_file), "--to", "notebook"])
      nb2 = nbformat.read(str(nb_file), as_version=4)
  
      compare_notebooks(nb2, nb)
  
file_path: jupytext/tests/functional/others/test_doxygen.py
imports: import nbformat
  import pytest
  import jupytext
  from jupytext.cli import jupytext
  from jupytext.compare import compare, compare_notebooks
  from jupytext.doxygen import doxygen_to_markdown, markdown_to_doxygen
label_desc: Use image node_id 4 for calling a global function with example usage: test_doxygen_equation_markers(tmpdir) without return types